Ask yourself these 4 questions:
1. Does the sentence begin with a verb? Then it is a verbal sentence.
2. Which action does the past form express?
3. Is its subject understood, attached as a pronoun, or written as an explicit noun after the verb?
4. Which separate pronoun corresponds to the form?
Common trap: Do not assume that every written ت represents the same doer. Compare شَرِبَتْ, خَلَقْتَ, ضَحِكْتِ, and قَرُبْتُ; their full endings and vowels are different.